Bitumen road composition and method of forming the same



Patented Nov. 15, 1932 UNITED STATES PATENT FF SAMUEL S. SADTLER, OF SPRINGFIELD TOWNSHIP, MONTGOMERY COUNTY PENNSYL- I VANIA, ASSIGNOR TO AMIESITE ASPHALT COMPANY OF AMERICA, OF PHILADEL- mm, PENNSYLVANIA, A oonroaarron on NEW JERSEY BITUMEN ROAD COMPOSITION ann mnrzron or FORMING'THE SAME No Drawing.

This invention relates to road construction, and more particularly to the type of roads employing a bitumen-coated aggregate of to provide novel means for obtaining a durable bond between the above-mentioned class of stone and the bitumen binder with which the stone is mixed in forming the road composition.

I have discovered thatrby first preparing the surfaces of the stone by treating the latter with a specially prepared bitumen solvent or liquefier including oleic acid or other oil-soluble fatty acid capable of combining with hydrated lime to form a soap practically insoluble in water and soluble in or easily wetted by oils and asphalt, and by thereafter adding the bitumen and a predetermined quantity of lime to react with the aforesaid fatty acid, the asphalt coating is made to adhere to the surface of the stone strongly and firmly and the tendency of the bitumen coating to be displaced is practically eliminated.

Although various liquefier materials may be used in preparing the stone surfaces for reception of the asphalt, I prefer to employ a mixture of relatively soft asphalt, having for example a penetration of from 100440, with kerosene or similar light oil, preferably also including a coal tar solvent of moderate volatility, such as drip oil. I have found,

however, that the use of a fatty acid, such as oleic, in a diluent such as kerosene, naphtha, or a compound solvent containing both of these substances or other organic liquids in which bitumens are more or less soluble,

Application filed December 16, 1926. Serial No. 155,348.

or so-called flux oil of high penetration,

say 100l40 and. after melting it add thereto two and one-half litres of the foregoing mixture of kerosene, drip oil and oleic acid.

NVhen themixture is completed, the final liquefier is a bituminousliquefier which remains quite fluid at normal temperatures and is of a dark brown or blackish color. y

In treating the limestone with this liquevfi er, Iadd it to the stone in proportions of about 'two gallons of the liquefier, moreor less, depending upon the character of the stone, to about 1900 pounds of graded stone. If the limestone is moderately hard, less liquefier is. required to coat it. In someexceptional cases,slightly more than two gallons of the liquefier may be required. When the liquefier is added, the'stone preferably is at a temperature of between 65 to 90 F.'

After the stone is fully wetted with this liquefier melted asphalt is added; For a top course, I prefer to use about 90 to 95 pounds of asphalt in addition to that in the liquefier to 1900 pounds'of stone, and for a bottom course or layer 65 to 85 pounds of asphalt 'may be used,depending somewhat upon the size of the aggregate. This asphalt or bituminous mixture is added preferably. at a temperatureof approximately 220 F and is fully incorporated with thestone that has previously been treated and wetted by the liquefier. Following the addition of and incorporation of the asphalt, hydrated limeis added in amount of approximately 6 to :10 pounds, and after its thorough admixture, the. batch is'ready for use. r v

In addition to the beneficial effect of the pretreatment of the aggregate, as described,

in facilitatingthe proper coating of the 7 stone, I consider the presence in the final mixture ofthe calcium oleate or other alkagives verygood results without the use of 7 line earth salt of a fatty acid to have a substantial water-proofing elfect.

I claim:

1. The method of forming bitumen road compositions,-which comprises taking a stone aggregate, coating the aggregate with a bituminous liquefier containing an oil soluble fatty acid capable of combining with hydrated lime to form a soap which is water-insoluble, and thereafter adding a normally solid bitumen binder in a heated liquid state and lime. g a

2. The method of forming road compositions, which consists in takinga stone aggregate, treating said aggregate with a bituminous liquefier containing soft asphalt of relatively high penetration and an oil-soluble fatty acid capable of combining with hydrated lime to form a water-insoluble soap, and thereafter incorporating a normally solid bitumen binder in heated liquid condition and lime.

3. The method of forming a road composition, which consists in taking a stone aggregate, treating the surfaces of the stone with a bituminous liqueiier containing soft asphalt of relatively high penetration, kerosene and an oil-soluble fatty acid capable of combining with hydrated lime to form awater-insoluble soap, the fatty acid content being more than ten per cent of the bituminous liquefier and thereafter incorporating a normally solid bitumen binder in heated liquid state and lime.

4. The method of forming a road composi tion, which consists in taking a stone aggregate, treating the surfaces of the stone with kerosene and an oil-soluble fatty acid capable of combining with hydrated lime to form a water-insoluble soap the quantity offatty acid being substantially one-half that of the kerosene, and thereafter incorporating a normally solid bitumen binder inheated liquid 7 state and lime,

5. The method of forming a road composition, which consists in taking a stone aggregate, treating the surfaces of said stone with a bituminous liquefier containing a soft asphalt of high penetration, kerosene, drip oil and an oil-soluble organic acid capable of combining with hydrated lime to form a soap which is insoluble in water, and thereafter incorporating a normally solid bitumen 6. The method of forming a road composition, which consists in taking a stone aggregate, treating the surfaces of said stone binder in heated liquid condition and lime.

with a bituminous liquefier containing more than ten per cent of oleic acid, and thereafter incorporating a bitumen binder and lime.

7. The method of forming a road compo- 4 sition, which consists in taking a stone aggregate, treating the surfaces of said stone'with a bituminous liquefier containing a fatty 

